I was using firefox lite(light?) version 40. I needed to reload the OS and when I got to that app to download I ran into issues. I found the app doing a search for it. The logo changed from FIREFOX LIGHT or just LIGHT to the letter "U", apparently representing the same app. The issue is that although I can find, download, the app, when I attempt to open it an error is displayed, "FILE NOT FOUND" or something similar. Does the app I knew as the third party version of firefox still exist? If yes where do I find and install it? I was using version 40. It has since been updated to 42. I tried version 34. Failure also. Apparently "U" has taken over the app. But if it will not open than it is of no use to me. Solutions please